Another name for electric cars is "coal-powered cars." That doesn't sit well with those who want to demonstrate their green bona fides by driving a plug-in vehicle. But it is in many cases accurate. Anyone who begs to differ can take up the argument with Chris Kennedy, a professor of civil engineering at the University of Toronto. He told the Canadian Broadcasting Corp. that, depending on the province, an electric car can produce more carbon dioxide than a gasoline-powered car.